CCC 953
© Libreria Editrice Vaticana Source: vatican.va
Communion in charity. In the sanctorum communio, "None of us lives to himself, and none of us dies to himself." Rom 14:7. "If one member suffers, all suffer together; if one member is honored, all rejoice together. Now you are the body of Christ and individually members of it." 1 Cor 12:26-27. "Charity does not insist on its own way." 1 Cor 13:5; cf. 10:24. In this solidarity with all men, living or dead, which is founded on the communion of saints, the least of our acts done in charity redounds to the profit of all. Every sin harms this communion.
Read the full chapter 3. I Believe in the Holy Spirit ¶683–1065